This invention relates to improvements in plastic containers and snap-on lids for such containers. More particularly, the invention relates to provision of a secondary sealing arrangement which has tamper resistant qualities as well as providing an hermetic seal. The invention is usable in a wide variety of environments which may include, by way of example only, containers for medicines in which it is desirable to provide a tamper resistant feature as well as containers for paint or for foods where it is desirable to package them for long shelf life in an hermetic seal. Additionally, it is among the general objects of the invention to provide a container and lid having these qualities yet which may be reusable and in which a highly effective reusable seal may be maintained by the main sealing structure. Thus, in accordance with the present invention, the tearaway sealing strip may be considered as an initial, but supplementary seal in addition to the primary reusable seal between the lid and the container.
The present invention may be utilized in conjunction with a lid of the type described in my U.S. Pat. No. 4,279,358 or in my co-pending application Ser. No. 379,746 which discloses a plastic lid in conjunction with a plastic can. The lid has a top wall and a circumferentially downwardly extending sidewall. The sidewall is shaped to cooperate with the lip at the upper end of the container to provide a special snap fit in which a thin web segment of the sidewall stretches about the lip and forms the primary reusable seal. The lower skirt portion of the sidewall is thicker and serves to constrict the sidewall about the lip of the container to draw and stretch the web against the lip.
In accordance with the present invention, a tearable strip is molded integrally and in one piece with the lid and extends from the lower portion of the lid skirt. The lower portion of the tear strip is secured, as by adhesive or thermal welding, directly to the sidewall of the container. The tear strip thus provides a continuous circumferentially tearable strip which spans and seals the skirt-container wall region. In the illustrative embodiment the invention is in the form of a detachable tearaway strip. The strip is at its weakest along the juncture to the lower edge of the skirt as well as along its point of connection to the sidewall of the container. The tear strip also is provided with an integrally molded starting tab which may be easily gripped by the user to initiate a tearaway action of the strip.
It is among the general objects of the invention to provide an improved plastic container and one-piece molded plastic lid having a snap-on seal and a secondary tamper resistant hermetic seal.
Another objective of the invention is to provide a container and lid of the type described having a tearaway strip which bridges and forms a one-piece continuous integral tamper proof seal between the container lid and the sidewall of the container.